Double-valve electric control shock absorber

Abstract

The utility model discloses a double-valve electric control shock absorber, which relates to the technical field of electric control shock absorbers, and adopts the technical scheme that the double-valve electric control shock absorber comprises a recovery electromagnetic valve, a compression electromagnetic valve, a liquid storage barrel, a steel barrel and a piston, two middle cylinders are arranged on the steel barrel, and a liquid storage cavity is formed between the two middle cylinders and the liquid storage barrel; a circulation cavity is formed between each middle cylinder and the steel cylinder, mounting shells are fixed to the outer side of the middle and the outer side of the lower portion of the liquid storage cylinder respectively, connecting sleeves communicated with the circulation cavities are arranged on the middle cylinders and located in the mounting shells, and limiting pieces used for limiting the connecting sleeves in the radial direction of the steel cylinder are fixed in the mounting shells. The recovery solenoid valve is installed in the installation shell located on the upper portion of the liquid storage cylinder, a one-way valve is arranged between the recovery solenoid valve and the corresponding connecting sleeve, and the compression solenoid valve is installed in the installation shell located on the lower portion of the liquid storage cylinder. The utility model can realize complete decoupling of recovery damping and compression damping, and has the advantages of good stability and long service life.

Description

Technical Field

[0001] The utility model relates to the technical field of electronically controlled shock absorbers, and more specifically, to a double-valve electronically controlled shock absorber. Background Art

[0002] Compared with the passive shock absorber whose damping force cannot be adjusted, the damping force of the electronically controlled shock absorber can be adjusted in real time, so the electronically controlled shock absorber can greatly improve the vehicle's driving performance. Single-valve electronically controlled shock absorbers are currently widely used by various OEMs in the industry due to their low cost. The oil inside the single-valve electronically controlled shock absorber can only pass through the same solenoid valve during the recovery and compression process, and the characteristics of the solenoid valve itself are fixed, so the recovery damping and compression damping of the single-valve electronically controlled shock absorber are affected by the same solenoid valve, resulting in the inability to decouple the recovery and compression damping, that is, the recovery damping and compression damping cannot be reduced separately. Therefore, during the tuning process, the tuning engineer must make a "balance" between the recovery damping and the compression damping. Therefore, the single-valve electronically controlled shock absorber is limited by its own structure, so that the vehicle's driving performance cannot be maximized.

[0003] Compared with single-valve electronically controlled shock absorbers, dual-valve electronically controlled shock absorbers have significant advantages, and can achieve independent adjustment of recovery and compression damping, thereby greatly improving the vehicle's driving performance. However, the dual-valve electronically controlled shock absorbers currently on the market are mostly simply copied based on the single solenoid valve design, and there are still the following problems:

[0004] 1. By simply setting two solenoid valves, during the compression stage of the shock absorber, the oil will flow through the restoring solenoid valve and the compression solenoid valve at the same time, and the compression damping will be affected by the two solenoid valves at the same time, resulting in the inability to completely decouple the restoring damping and the compression damping, greatly reducing the damping adjustability of the shock absorber;

[0005] 2. The two solenoid valves directly apply force to the steel cylinder, which will be subjected to a large lateral force, causing the steel cylinder to be easily bent and deformed, which in turn leads to problems such as limited adjustability of the damping force value, increased friction, and increased durability and fatigue risk.

[0006] Therefore, a new solution needs to be proposed to solve this problem. Utility Model Content

[0007] In view of the deficiencies in the prior art, the purpose of the utility model is to provide a dual-valve electronically controlled shock absorber which can achieve complete decoupling of restoring damping and compression damping and has the advantages of good stability and long service life.

[0008] The above technical objectives of the utility model are achieved through the following technical solutions: a double-valve electronically controlled shock absorber, comprising a restoring solenoid valve, a compression solenoid valve, a liquid storage cylinder, a steel cylinder arranged in the liquid storage cylinder and a piston arranged in the steel cylinder, two intermediate cylinders are arranged on the steel cylinder, the two intermediate cylinders are respectively located at the upper part and the lower part of the steel cylinder, a liquid storage cavity is formed between the two intermediate cylinders and the liquid storage cylinder, a flow cavity is respectively formed between each intermediate cylinder and the steel cylinder, and a flow hole connected with each flow cavity is respectively arranged on the steel cylinder, a mounting shell is respectively fixed to the outer side of the middle part and the outer side of the lower part of the liquid storage cylinder, a connecting sleeve connected with the flow cavity is respectively arranged on each intermediate cylinder and located in the mounting shell, a limiting member for limiting the connecting sleeve along the radial direction of the steel cylinder is fixed in the mounting shell, the restoring solenoid valve is installed in the mounting shell located at the upper part of the liquid storage cylinder, a one-way valve is arranged between the restoring solenoid valve and the corresponding connecting sleeve, and the compression solenoid valve is installed in the mounting shell located at the lower part of the liquid storage cylinder and is tightly connected with the corresponding connecting sleeve.

[0009] In one of the embodiments, each of the intermediate cylinders is respectively sleeved and fixed on a steel cylinder, and a first sealing ring is respectively provided between the two ends of each intermediate cylinder and the steel cylinder.

[0010] In one of the embodiments, an opening communicating with the flow chamber is provided on the side wall of the intermediate cylinder, an annular flange is provided on the intermediate cylinder around the opening, the connecting sleeve comprises a hollow cylindrical portion and an annular disc portion, an annular groove is provided on the outer peripheral wall of the hollow cylindrical portion, a second sealing ring is provided on the annular groove, the hollow cylindrical portion extends into the annular flange, and the second sealing ring is tightly attached to the annular flange, the limiting member is an annular boss, one end of the annular disc portion abuts against the annular boss, and the other end abuts against the one-way valve.

[0011] In one embodiment, the one-way valve includes an upper seat, a lower seat, a valve plate and a wave spring, the upper seat is a hollow cylindrical component with an opening at one end, the lower seat is interference fit connected to the opening position of the upper seat, the upper seat and the lower seat are provided with regular through holes along their axial positions, the lower seat is provided with a plurality of oil flow holes around the regular through holes, a cavity is formed between the upper seat and the lower seat, the valve plate and the wave spring are both arranged in the cavity, and the wave spring can press the valve plate against the end face of the lower seat to block the oil flow hole, the lower seat is also provided with a positioning boss for circumferentially positioning the valve plate, the valve plate is annular, and the valve plate is sleeved on the positioning boss.

[0012] In one embodiment, the restoring solenoid valve and the compression solenoid valve are both connected to the mounting housing via a threaded structure.

[0013] In one of the embodiments, the dual-valve electronically controlled shock absorber further includes a connecting rod, one end of which is slidably connected to the top of the fluid storage cylinder, and the other end of which is fixedly connected to the piston.

[0014] In one embodiment, the piston divides the interior of the steel cylinder into a recovery chamber and a compression chamber, the recovery chamber is located at the upper part of the steel cylinder, and the compression chamber is located at the lower part of the steel cylinder. A recovery valve system is provided on the piston, and a compression valve system is provided at the bottom of the steel cylinder. There is a spare chamber below the compression valve system, and the spare chamber is connected to the liquid storage chamber.

[0015] In summary, the utility model has the following beneficial effects:

[0016] 1. By setting a one-way valve between the restoring solenoid valve and the connecting sleeve, the oil of the shock absorber cannot flow through the restoring solenoid valve during compression, but can only flow through the compression solenoid valve, thereby achieving complete decoupling of the restoring damping and the compression damping, so that the restoring damping and the compression damping can be adjusted independently;

[0017] 2. By arranging a limiter in the installation shell for limiting the radial position of the connecting sleeve along the steel cylinder, the limiter will limit the connecting sleeve along the radial direction of the steel cylinder, so that the force when the restoration solenoid valve and the compression solenoid valve are locked can be completely borne by the installation shell and the limiter, so that the steel cylinder is not easy to bend and deform, which is beneficial to improve the stability and service life of the shock absorber. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 A cross-sectional view of a dual-valve electronically controlled shock absorber according to an embodiment of the present application;

[0019] Figure 2 for Figure 1 A magnified view of section A;

[0020] Figure 3 for Figure 1 A magnified schematic diagram of part B in FIG.

[0021] Figure 4 This is a schematic diagram of the structure of a one-way valve in a dual-valve electronically controlled shock absorber according to an embodiment of the present application;

[0022] Figure 5 A schematic diagram of a compression state of a dual-valve electronically controlled shock absorber according to an embodiment of the present application;

[0023] Figure 6 It is a schematic diagram of the recovery state of the dual-valve electronically controlled shock absorber according to an embodiment of the present application.

[0024] In the figure: 1. liquid storage cylinder; 2. intermediate cylinder; 3. steel cylinder; 4. connecting rod; 5. piston; 6. restoring solenoid valve; 7. compression solenoid valve; 8. compression valve system; 9. first sealing ring; 10. restoring chamber; 11. liquid storage chamber; 12. compression chamber; 13. circulation hole; 14. mounting shell; 15. limiter; 16. connecting sleeve; 17. second sealing ring; 18. circulation chamber; 19. one-way valve; 191. upper seat; 192. lower seat; 1921. positioning boss; 1922. oil circulation hole; 1923. flange; 193. valve plate; 194. wave spring; 195. normal through hole. DETAILED DESCRIPTION

[0025] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0026] like Figures 1 to 4 As shown, the embodiment of the present application provides a dual-valve electronically controlled shock absorber, including a restoring solenoid valve 6, a compression solenoid valve 7, a liquid storage cylinder 1, a steel cylinder 3 disposed in the liquid storage cylinder 1, and a piston 5 disposed in the steel cylinder 3. Two intermediate cylinders 2 are disposed on the steel cylinder 3, and the two intermediate cylinders 2 are respectively located at the upper part and the lower part of the steel cylinder 3. The intermediate cylinder 2 located at the upper part of the steel cylinder 3 at least extends to the lower middle part of the liquid storage cylinder 1. A liquid storage cavity 11 is formed between the two intermediate cylinders 2 and the liquid storage cylinder 1, and a flow cavity 18 is formed between each intermediate cylinder 2 and the steel cylinder 3. The steel cylinder 3 is respectively provided with a flow hole 13 connected with each flow cavity 18, wherein one flow hole 13 is located above the restoring solenoid valve 6, and the other flow hole 13 is located below the compression solenoid valve 7. The outer middle part and the outer lower part of the liquid storage cylinder 1 are respectively fixed with a mounting shell 14, and each intermediate cylinder 2 is provided with a connecting sleeve 16 connected with the flow chamber 18 in the mounting shell 14, and a limiting member 15 for limiting the connecting sleeve 16 along the radial direction of the steel cylinder 3 is fixed in the mounting shell 14. The restoration solenoid valve 6 is installed in the mounting shell 14 located at the upper part of the liquid storage cylinder 1, and a one-way valve 19 is provided between the restoration solenoid valve 6 and the corresponding connecting sleeve 16. The compression solenoid valve 7 is installed in the mounting shell 14 located at the lower part of the liquid storage cylinder 1, and is tightly connected with the corresponding connecting sleeve 16. The restoration solenoid valve 6 and the compression solenoid valve 7 both include a liquid inlet and a liquid outlet, and the specific detailed structure adopts the existing technology, which will not be repeated in this embodiment.

[0027] In the above manner, to sum up, the utility model has the following beneficial effects: by arranging a one-way valve 19 between the restoring solenoid valve 6 and the connecting sleeve 16, during the compression process, the oil of the shock absorber cannot flow through the restoring solenoid valve 6, but can only flow through the compression solenoid valve 7, thereby realizing complete decoupling of the restoring damping and the compression damping, so that the restoring damping and the compression damping can be adjusted independently; by arranging a limit member 15 for limiting the connecting sleeve 16 along the radial direction of the steel cylinder 3 in the mounting shell 14, the limit member 15 will limit the connecting sleeve 16 along the radial direction of the steel cylinder 3, so that the force when the restoring solenoid valve 6 and the compression solenoid valve 7 are locked can be completely borne by the mounting shell 14 and the limit member 15, so that the steel cylinder 3 is not easy to bend and deform, which is beneficial to improve the stability and service life of the shock absorber.

[0028] In this embodiment, each of the intermediate cylinders 2 is respectively sleeved and fixed on the steel cylinder 3, and a first sealing ring 9 is respectively arranged between the two ends of each intermediate cylinder 2 and the steel cylinder 3. The arrangement of the first sealing ring 9 effectively ensures the sealing between the intermediate cylinder 2 and the steel cylinder 3, and prevents the oil from leaking from the interface during the operation of the shock absorber.

[0029] In this embodiment, an opening connected to the circulation chamber 18 is provided on the side wall of the intermediate cylinder 2, and an annular flange is provided around the opening on the intermediate cylinder 2. The connecting sleeve 16 includes a hollow cylindrical portion and an annular disc portion. An annular groove is provided on the outer peripheral wall of the hollow cylindrical portion, and a second sealing ring 17 is provided on the annular groove. The hollow cylindrical portion extends into the annular flange, and the second sealing ring 17 is tightly attached to the annular flange. The limiting member 15 is an annular boss, and one end of the annular disc portion abuts against the annular boss, and the other end abuts against the one-way valve 19.

[0030] In the above manner, the design of the connecting sleeve enables it to be easily inserted into the annular flange and sealed by the second sealing ring 17. At the same time, the setting of the limiter 15 ensures the accurate positioning of the connecting sleeve 16 in the axial and radial directions. At the same time, the limiter 15 will limit the connecting sleeve 16 along the radial direction of the steel cylinder 3, so that the force applied when the restoration solenoid valve 6 and the compression solenoid valve 7 are locked can be completely borne by the installation shell 14 and the limiter 15, so that the steel cylinder 3 is not easy to bend and deform.

[0031] In this embodiment, the one-way valve 19 includes an upper seat 191, a lower seat 192, a valve plate 193 and a wave spring 194. The upper seat 191 is a hollow cylindrical member with an opening at one end. The lower seat 192 is connected to the opening position of the upper seat 191 by interference fit. The upper seat 191 and the lower seat 192 are provided with a regular through hole 195 along their axial position. The lower seat 192 is provided with a plurality of oil flow holes 1922 around the regular through hole 195. The upper seat 191 and the lower seat 192 are formed between There is a cavity, the valve plate 193 and the wave spring 194 are both arranged in the cavity, and the wave spring 194 can press the valve plate 193 against the end face of the lower seat 192 to block the oil flow hole 1922. The lower seat 192 is also provided with a positioning boss 1921 for circumferential positioning of the valve plate 193. The valve plate 193 is annular, and the valve plate 193 is sleeved on the positioning boss 1921. The lower seat 192 is surrounded by a flange 1923 for limiting the upper seat 191.

[0032] In the above manner, the one end of the one-way valve 19 close to the restoration solenoid valve 6 is the outlet, and the one end close to the liquid storage chamber 11 is the inlet. The connecting sleeve 16 is provided with a channel for the oil in the liquid storage chamber 11 to flow into the oil flow hole 1922. During operation, when there is no external oil pressure, the wave spring 194 presses the valve plate 193 tightly against the end surface of the lower seat 192. At this time, the oil flow hole 1922 is completely blocked by the valve plate 193, and the oil cannot pass through the flow hole 13 of the lower seat 192. This state ensures that when there is no external pressure, the oil will not flow from the lower seat 192 to the upper seat 191. When oil enters from the upper seat 191 and applies sufficient pressure, the oil pressure will overcome the elastic force of the wave spring 194, push the valve plate 193 to move upward, and thus open the oil flow hole 1922. At this time, the oil can flow out from the lower seat 192 through these flow holes 13 to achieve one-way flow. The design of the one-way valve 19 adopts a combination of a wave spring 194 and a valve plate 193, ensuring that the oil will not flow in the opposite direction when there is no external pressure, thereby improving the reliability and stability of the system.

[0033] In this embodiment, the restoration solenoid valve 6 and the compression solenoid valve 7 are connected to the mounting housing 14 through a threaded structure. Specifically, an external thread is provided on the outer peripheral wall of the restoration solenoid valve 6 and the compression solenoid valve 7, and an internal thread is provided on the inner peripheral wall of the mounting housing 14, and the external thread is threadedly connected to the internal thread. The design of connecting the restoration solenoid valve 6 and the compression solenoid valve 7 to the mounting housing 14 through a threaded structure has the beneficial effects of firm and reliable connection, convenient installation and disassembly, strong adaptability, excellent sealing performance and high degree of standardization.

[0034] In this embodiment, the dual-valve electronically controlled shock absorber further includes a connecting rod 4 , one end of which is slidably connected to the top of the liquid storage cylinder 1 , and the other end of which is fixedly connected to the piston 5 .

[0035] In this embodiment, the piston 5 divides the interior of the steel cylinder 3 into a recovery chamber 10 and a compression chamber 12, the recovery chamber 10 is located at the upper part of the steel cylinder 3, and the compression chamber 12 is located at the lower part of the steel cylinder 3. The piston 5 is provided with a recovery valve system, and the bottom of the steel cylinder 3 is provided with a compression valve system 8. There is a spare chamber below the compression valve system 8, and the spare chamber is connected to the liquid storage chamber 11. The recovery valve system and the compression valve system 8 are both pressure relief valves.

[0036] The working principle of the dual-valve electronically controlled shock absorber of this application is:

[0037] like Figure 5 As shown, during the compression process, the connecting rod 4 moves downward, the restoring chamber 10 becomes a low-pressure chamber, the outlet pressure of the one-way valve 19 is less than the inlet pressure, and the oil in the liquid storage chamber 11 pushes open the one-way valve 19 under the action of the inflation force, passes through the normal through hole 195, the connecting sleeve 16 and the flow chamber 18, and then flows into the restoring chamber 10 along the flow hole 13 of the steel cylinder 3, so as to replenish the oil in the restoring chamber 10; at the same time, during the compression process, the compression chamber 12 forms a high pressure, a part of the oil flows to the liquid storage chamber 11 through the compression valve system 8, and the other part of the oil flows into the liquid storage chamber 11 through the circulation of the steel cylinder 3 below, the liquid storage chamber 11 and the connecting sleeve 16, and then flows into the liquid storage chamber 11 through the compression solenoid valve 7. During the compression process, the oil inside the shock absorber will not flow through the restoring solenoid valve 6, but will only flow through the compression solenoid valve 7.

[0038] It should be noted that the liquid storage chamber 11 is filled with nitrogen. When the connecting rod 4 drives the piston 5 to move downward, the pressure in the recovery chamber 10 decreases and is smaller than the gas force in the liquid storage chamber 11, so that the oil in the liquid storage chamber 11 can push open the one-way valve 19.

[0039] like Figure 6 As shown, during the recovery process, the connecting rod 4 moves upward, the recovery chamber 10 becomes a high-pressure chamber, and the outlet pressure of the one-way valve 19 is greater than the inlet pressure, so that the one-way valve 19 does not open during the recovery process, and the oil cannot flow into the liquid storage chamber 11 through the one-way valve 19, but can only flow into the liquid storage chamber 11 through the recovery solenoid valve 6. At the same time, during the recovery process, the compression chamber 12 forms a low pressure, and a part of the oil in the recovery chamber 10 flows through the recovery solenoid valve 6, and another part of the oil passes through the recovery valve system and flows from the recovery chamber 10 into the compression chamber 12; at the same time, during the recovery process, the pressure of the compression chamber 12 is lower than the pressure of the liquid storage chamber 11, that is, the inlet pressure of the compression solenoid valve 7 is lower than the outlet pressure, so during the recovery process, the oil will not flow through the compression solenoid valve 7.

[0040] To sum up, during the restoration process, the internal oil only flows through the restoration solenoid valve 6 and does not flow through the compression solenoid valve 7. Adding a one-way valve 19 at the front end of the restoration solenoid valve 6 can make the internal oil only flow through the compression solenoid valve 7 and not through the restoration solenoid valve 6 during the compression process of the shock absorber, thereby completely decoupling the restoration damping and compression damping of the dual-valve electronically controlled shock absorber.

[0041] The above is only a preferred embodiment of the present invention. The protection scope of the present invention is not limited to the above embodiments. All technical solutions under the concept of the present invention belong to the protection scope of the present invention. It should be pointed out that for ordinary technicians in this technical field, some improvements and modifications without departing from the principle of the present invention should also be regarded as the protection scope of the present invention.

Claims

1. A dual-valve electronically controlled shock absorber, comprising a restoring solenoid valve (6), a compression solenoid valve (7), a liquid storage cylinder (1), a steel cylinder (3) disposed in the liquid storage cylinder (1), and a piston (5) disposed in the steel cylinder (3), characterized in that: The steel cylinder (3) is provided with two intermediate cylinders (2), the two intermediate cylinders (2) are respectively located at the upper part and the lower part of the steel cylinder (3), a liquid storage cavity (11) is formed between the two intermediate cylinders (2) and the liquid storage cylinder (1), a flow cavity (18) is respectively formed between each intermediate cylinder (2) and the steel cylinder (3), and a flow hole (13) connected to each flow cavity (18) is respectively provided on the steel cylinder (3), a mounting shell (14) is respectively fixed to the outer side of the middle part and the outer side of the lower part of the liquid storage cylinder (1), and each intermediate cylinder (2) is located in the mounting shell (14) and has a plurality of holes (13) connected to each of the holes (13) and the plurality of holes (13) connected to each of the holes (18) respectively. A connecting sleeve (16) is provided which is in communication with the circulation cavity (18); a limiting member (15) is fixed in the mounting shell (14) for limiting the radial direction of the connecting sleeve (16) of the steel cylinder (3); the restoring solenoid valve (6) is installed in the mounting shell (14) located at the upper part of the liquid storage cylinder (1); a one-way valve (19) is provided between the restoring solenoid valve (6) and the corresponding connecting sleeve (16); the compression solenoid valve (7) is installed in the mounting shell (14) located at the lower part of the liquid storage cylinder (1) and is tightly connected to the corresponding connecting sleeve (16).

2. The dual-valve electronically controlled shock absorber according to claim 1, characterized in that: Each of the intermediate cylinders (2) is sleeved and fixed on the steel cylinder (3), and a first sealing ring (9) is provided between the two ends of each intermediate cylinder (2) and the steel cylinder (3).

3. The dual-valve electronically controlled shock absorber according to claim 1, characterized in that: The side wall of the intermediate cylinder (2) is provided with an opening connected to the circulation chamber (18); the intermediate cylinder (2) is provided with an annular flange around the opening; the connecting sleeve (16) comprises a hollow columnar portion and an annular disc portion; an annular groove is provided on the outer peripheral wall of the hollow columnar portion; a second sealing ring (17) is provided on the annular groove; the hollow columnar portion extends into the annular flange so that the second sealing ring (17) is tightly attached to the annular flange; the limiting member (15) is an annular boss; one end of the annular disc portion abuts against the annular boss, and the other end abuts against the one-way valve (19).

4. The dual-valve electronically controlled shock absorber according to claim 1, characterized in that: The one-way valve (19) comprises an upper seat (191), a lower seat (192), a valve plate (193) and a wave spring (194); the upper seat (191) is a hollow columnar component with an opening at one end; the lower seat (192) is connected to the opening of the upper seat (191) by interference fit; a through hole (195) is provided along the axis of the upper seat (191) and the lower seat (192); a plurality of oil flow holes (1922) are provided around the through hole (195) on the lower seat (192); A cavity is formed between the upper and lower seats (191) and the lower seat (192), the valve plate (193) and the wave spring (194) are both arranged in the cavity, and the wave spring (194) can press the valve plate (193) against the end surface of the lower seat (192) to block the oil flow hole (1922), and the lower seat (192) is also provided with a positioning boss (1921) for circumferentially positioning the valve plate (193), the valve plate (193) is annular, and the valve plate (193) is sleeved on the positioning boss (1921).

5. The dual-valve electronically controlled shock absorber according to claim 1, characterized in that: The restoring solenoid valve (6) and the compression solenoid valve (7) are both connected to the mounting housing (14) via a threaded structure.

6. The dual-valve electronically controlled shock absorber according to claim 1, characterized in that: The dual-valve electronically controlled shock absorber further comprises a connecting rod (4), one end of which is slidably connected to the top of the liquid storage cylinder (1) and the other end of which is fixedly connected to the piston (5).

7. The dual-valve electronically controlled shock absorber according to claim 1, characterized in that: The piston (5) divides the interior of the steel cylinder (3) into a recovery chamber (10) and a compression chamber (12); the recovery chamber (10) is located at the upper part of the steel cylinder (3), and the compression chamber (12) is located at the lower part of the steel cylinder (3); a recovery valve system is provided on the piston (5), and a compression valve system (8) is provided at the bottom of the steel cylinder (3); a spare chamber is provided below the compression valve system (8), and the spare chamber is connected to the liquid storage chamber (11).

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